Heat exchanging system for vehicle and control method thereof

ABSTRACT

A heat exchange system for a vehicle may include a heat exchanger to transfer heat among a coolant, an automatic transmission oil, and/or a gear oil, an engine fluidly connected to the heat exchanger and adapted to deliver/receive the coolant, an automatic transmission fluidly connected to the heat exchanger and adapted to deliver/receive the automatic transmission oil, a differential apparatus fluidly connected to the heat exchanger and adapted to deliver/receive the gear oil, a pump adapted to pump the gear oil, and a control unit adapted to control the pump. A control method is also provided.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority of Korean Patent Application Number No. 10-2011-0042679 filed in the Korean Intellectual Property Office on May 4, 2011, the entire contents of which application are incorporated herein for all purposes by this reference.

BACKGROUND OF INVENTION

1. Field of Invention

The present invention relates to a heat exchange system for a vehicle and a control method thereof. More particularly, the present invention relates to a heat exchange system and a control method thereof that can be applied simultaneously to an automatic transmission and a differential apparatus of a vehicle.

2. Description of Related Art

Generally, a heat exchange system leads heat exchange between a heat source of high temperature and a heat source of low temperature so as to warm up a fluid of low temperature and cool a fluid of high temperature.

The heat exchange system can be applied to a driving device of a vehicle. Herein, the driving device represents a power delivery device of a vehicle including an automatic transmission or a manual transmission. In a power delivery device of a vehicle using an automatic transmission, oil in the automatic transmission and the differential apparatus has characteristics such that viscosity thereof becomes lowered as temperature thereof rises. Considering such characteristics, mechanical friction can be reduced through a quick warm-up of the automatic transmission. Therefore, a quick warm-up of the power delivery device has been researched for improving fuel economy of the vehicle.

According to conventional arts, a device for increasing oil temperature is not applied to the automatic transmission and the differential apparatus, or a heat exchange system for increasing oil temperature only in the automatic transmission is used. Therefore, it is not easy to warm up oil in the differential apparatus and optimal fuel economy may not be gained.

The information disclosed in this Background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

SUMMARY OF INVENTION

Various aspects of the present invention have been made in an effort to provide a heat exchange system for a vehicle and a control method thereof having advantages of being applied simultaneously to an automatic transmission and a differential apparatus.

In addition, other aspects of the present invention have been directed to provide a heat exchange system for a vehicle and a control method thereof that can minimize unnecessary cooling loss and improves fuel economy of a vehicle and durability of a driving device.

Exemplary heat exchange systems for a vehicle according to the present invention may include a heat exchanger adapted to transfer heat among a coolant, an automatic transmission oil, and/or a gear oil, an engine fluidly connected to the heat exchanger and adapted to deliver the coolant to the heat exchanger or to receive the coolant from the heat exchanger, an automatic transmission fluidly connected to the heat exchanger and adapted to deliver the automatic transmission oil to the heat exchanger or to receive the automatic transmission oil from the heat exchanger, a differential apparatus fluidly connected to the heat exchanger and adapted to deliver the gear oil to the heat exchanger or to receive the gear oil from the heat exchanger, a pump adapted to pump the gear oil, and a control unit adapted to control the pump.

A coolant pathway through which the coolant flows, a transmission oil pathway through which the automatic transmission oil flows, and a gear oil pathway through which the gear oil flows may be formed in the heat exchanger, and the coolant pathway, the transmission oil pathway, and the gear oil pathway may be not fluidly communicated with each other.

The coolant, the automatic transmission oil, and/or the gear oil may transfer heat with each other during passing respectively through the coolant pathway, the transmission oil pathway, and/or the gear oil pathway.

The pump may be provided at the differential apparatus.

The control unit may be adapted to receive information on the coolant, the automatic transmission oil, and/or the gear oil, and to control a rotation speed of the pump or to turn on or off the pump selectively based on the information.

The heat exchange system may further include a heater adapted to receive the coolant from the engine, warm up the coolant and return the coolant back to the engine, and a radiator adapted to receive the coolant from the engine, cool the coolant and return the coolant back to the engine.

An exemplary control method for exemplary heat exchange systems according to the present invention may include determining whether information on temperatures of the coolant, the automatic transmission oil, and the gear oil is received during an operation of the engine, calculating a rotation speed of the pump according to the information if the information is received, and operating the pump according to the calculated rotation speed.

The pump may be operated at a safe mode in a case that the information is not received. The pump may be operated only when the engine operates.

The control method may further include diagnosing the pump if the vehicle is in a key-on state before the engine operates.

Another exemplary control method for exemplary heat exchange systems according to the present invention may include determining whether information on temperatures of the coolant, the automatic transmission oil, and the gear oil is received during an operation of the engine, and turning on or off the pump selectively based on the information if the information is received.

The pump may be turned off so as to prevent heat loss of the coolant in a case that a coolant temperature is lower than a first predetermined temperature.

The pump may be turned on so as to increase a heat-exchange efficiency between the oil and the coolant in a case that the coolant temperature is higher than or equal to the first predetermined temperature and an oil temperature is lower than a second predetermined temperature.

The pump may be turned off so as to minimize wasting energy of the heat exchange system in a case that the oil temperature is higher than or equal to the second predetermined temperature and is lower than a third predetermined temperature.

The pump may be turned on so as to prevent overheating of the automatic transmission and the differential apparatus in a case that the oil temperature is higher than or equal to a third predetermined temperature.

The pump may be operated at a safe mode in a case that the information is not received. The pump may be operated only when the engine operates.

The another control method may further include diagnosing the pump if the vehicle is in a key-on state before the engine operates.

The methods and apparatuses of the present invention have other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following Detailed Description, which together serve to explain certain principles of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a driving device provided with exemplary heat exchange systems according to the present invention.

FIG. 2 is a schematic diagram of an exemplary heat exchange system for a vehicle according to the present invention.

FIG. 3 is a flowchart of an exemplary control method for controlling exemplary heat exchange systems according to the present invention.

FIG. 4 is a flowchart of another exemplary control method for controlling exemplary heat exchange systems according to the present invention.

DETAILED DESCRIPTION

Reference will now be made in detail to various embodiments of the present invention(s), examples of which are illustrated in the accompanying drawings and described below. While the invention(s) will be described in conjunction with exemplary embodiments, it will be understood that present description is not intended to limit the invention(s) to those exemplary embodiments. On the contrary, the invention(s) is/are intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims.

As shown in FIG. 1, exemplary heat exchange systems according to the present invention include an engine 10, a heater 20, a radiator 30, and a thermostat 40, and the constituent elements 10, 20, 30, and 40 are connected to each other through a coolant pathway 100.

A coolant passing through the engine 10 and the heater 20 flows in a heat exchanger 90 through the coolant pathway 100. In addition, the coolant passing through heat exchanger 90 returns back to the engine 10 through the coolant pathway 100. The coolant is warmed up by the heater 20.

On the other hand, the coolant flowing out from the engine 10 passes through the radiator 30 and the thermostat 40 and returns back to the engine 10. The coolant is cooled by the radiator 30.

Further, the heat exchanger 90 is connected to a differential apparatus 70 and an automatic transmission 80.

Referring to FIG. 2, exemplary heat exchange systems according to the present invention will be described in detail.

As shown in FIG. 2, the heat exchange system for a vehicle according to various embodiments of the present invention includes the heat exchanger 90 which raises or lowers temperatures of the coolant, an automatic transmission oil, and a gear oil, a pump 60 pumping the gear oil, and a control unit 50 controlling the pump 60.

A coolant inlet 102, a coolant outlet 104, a gear oil inlet 112, a gear oil outlet 114, a transmission oil inlet 122, and a transmission oil outlet 124 are formed at the heat exchanger 90. In addition, the heat exchanger 90 is provided with a coolant pathway 100, a gear oil pathway 110, and a transmission oil pathway 120 formed therein.

The coolant heat-exchanges with the engine 10, the automatic transmission oil heat-exchanges with the automatic transmission 80, and the gear oil heat-exchanges with the differential apparatus 70 at the exterior of the heat exchanger 90. In addition, the coolant, the automatic transmission oil, and the gear oil heat-exchange with each other in the heat exchanger 90.

For achieving heat-exchange among the coolant, the automatic transmission oil, and/or the gear oil, a person skilled in the art will appreciate that the coolant pathway 100, the gear oil pathway 110, and the transmission oil pathway 120 in the heat exchanger 90 can be arranged in a variety of ways.

As described above, three types of fluid are simultaneously heat-exchanged with each other according to various embodiments of the present invention, and thus cooling loss and heat loss may be minimized.

The coolant pathway 100 in the heat exchanger 90 has an end connected to the coolant inlet 102 and the other end connected to the coolant outlet 104. The coolant pathway 100 in the heat exchanger 90, as shown in FIG. 1, is connected to the engine 10 through the coolant inlet 102 or the coolant outlet 104. In addition, the coolant pathway 100 can be connected to the engine 10 through other devices.

The coolant flowing out from the engine 10 passes sequentially or substantially sequentially through the coolant inlet 102, the coolant pathway 100 in the heat exchanger 90, and the coolant outlet 104 and returns back to the engine 10.

The gear oil pathway 110 in the heat exchanger 90 has an end connected to the gear oil inlet 112 and the other end connected to the gear oil outlet 114. The gear oil pathway 110 in the heat exchanger 90, as shown in FIG. 2, is connected to the differential apparatus 70 through the gear oil inlet 112 or the gear oil outlet 114. In addition, at least one of the gear oil inlet 112 and the gear oil outlet 114 is connected to the pump 60 provided at the differential apparatus 70.

The gear oil flowing out from the differential apparatus 70 passes sequentially or substantially sequentially through the gear oil inlet 112, the gear oil pathway 110 in the heat exchanger 90, and the gear oil outlet 114 and returns back to the differential apparatus 70. In addition, the gear oil flows in the differential apparatus 70 after passing through the pump 60 or flows out from the differential apparatus 70 after passing through the pump 60.

The transmission oil pathway 120 in the heat exchanger 90 has an end connected to the transmission oil inlet 122 and the other end connected to the transmission oil outlet 124. The transmission oil pathway 120 in the heat exchanger 90, as shown in FIG. 2, is connected to the automatic transmission 80 through the transmission oil inlet 122 or the transmission oil outlet 124.

The automatic transmission oil flowing out from the automatic transmission 80 passes sequentially or substantially sequentially through the transmission oil inlet 122, the transmission oil pathway 120 in the heat exchanger 90, and the transmission oil outlet 124 and returns back to the automatic transmission 80.

As described above, the coolant, the automatic transmission oil, and the gear oil are heat-exchanged with each other during passing respectively through the coolant pathway 100, the transmission oil pathway 120, and the gear oil pathway 110 in the heat exchanger 90.

Herein, the gear oil (differential oil) represents all the oil used for lubricating the differential apparatus (differential gear). In addition, an automatic transmission fluid (ATF) can be used as the automatic transmission oil, but is not limited to this.

The pump 60 is provided at the differential apparatus 70. The pump 60 is connected to at least one of the gear oil inlet 112 and the gear oil outlet 114 and pumps the gear oil. Therefore, the pump 60 facilitates circulation of the gear oil in the differential apparatus 70 or flowing of the gear oil in the heat exchanger 90. An electric pump may be used as pump 60, but is not limited to this.

The control unit 50 is electrically connected to the pump 60. In addition, the control unit 50 is electrically connected to the engine 10 and the automatic transmission 80. The control unit 50 receives information (e.g., temperature and/or speed) on the coolant, the automatic transmission oil, and/or the gear oil. In addition, the control unit 50 controls a rotation speed of the pump 60 or turns on or off the pump 60 selectively based on the received information.

Referring to FIG. 3 and FIG. 4, a control method of the heat exchange system according to various embodiments of the present invention will be described in detail.

As shown in FIG. 3, if the vehicle becomes a key-on state at a step S100, the control unit 50 begins diagnosis of the pump 60 at a step S110.

If diagnosis of the pump 60 is begun, the control unit 50 delivers a signal for operating the pump 60 to the pump 60 at a stet S120.

If the pump 60 receives the signal and operates, the control unit 50 receives a signal regarding operating condition of the pump 60 and determines whether the pump 60 operates normally at a step S130. A normal operation of the pump 60 means that the pump 60 is not out of order or sensors detecting conditions of the pump 60 are not out of order.

If the pump 60 does not operate normally (e.g., the pump 60 is out of order or the sensors detecting the conditions of the pump 60 are out of order), the control unit 50 operates a warning device such as a warning lamp at a step S180. The warning lamp may be provided at a cluster such that a driver can recognize the conditions of the pump 60.

If the pump 60 operates normally, the control unit 50 stops the operation of the pump 60 and preparing the operation of the pump 60 at a step S140. In addition, the step S140 can be completed before the engine 10 is started.

If the engine 10 operates at a step S150, the control unit 50 determines whether information on temperatures of the oil and the coolant is received at a step S160. The oil represents the gear oil for lubricating the differential apparatus 70. In general, a temperature difference between the gear oil and the automatic transmission oil is not large, so either a temperature of the automatic transmission oil or a temperature of the gear oil can be used as the oil temperature. In addition, the oil temperature is an oil temperature in the differential apparatus 70 or the automatic transmission 80 and the coolant temperature is a coolant temperature before flowing into the heat exchanger 90 according to various embodiments of the present invention. However, the oil temperature and the coolant temperature can be defined in other ways.

If the information on the temperatures of the oil and the coolant is not received, the control unit 50 operates the pump 60 at a safe mode at a step S170. The safe mode is a mode where the pump 60 operates safely. The operation of the pump 60 at the safe mode can be set in an otherwise conventional way. In addition, if the pump 60 operates at the safe mode, the control unit 50 operates the warning lamp at the step S180.

If the information on the temperatures of the oil and the coolant is received, the control unit 50 calculates a rotation speed of the pump 60 according to the information at a step S200.

If the rotation speed of the pump 60 is calculated, the control unit 50 operates the pump 60 according to the calculated rotation speed at a step S210. The rotation speed according to the information can be set according to a target pump performance in an otherwise conventional way. The steps of S160 to S180 and the steps of S200 to S210 are repeated during the engine operates.

During the operation of the pump 60, the control unit 50 determines whether the engine 10 is stopped at a step S220. If the engine 10 is not stopped, the control unit 50 returns to the step S160. If the engine 10 is stopped, the control unit 50 stops the pump 60 at a step S230.

FIG. 4 is a flowchart of another exemplary control method for controlling exemplary heat exchange systems according to the present invention. The steps of S100 to S150 and the step of S180 in FIG. 4 are the same as those in FIG. 3, and thus detailed description thereof will be omitted.

As shown in FIG. 4, if the engine begins to operate at the step S150, the control unit 50 determines whether information on the temperatures of the oil and the coolant is received at the step S160. If the information on the temperatures of the oil and the coolant is received, the control unit 50 determines whether the coolant temperature is lower than a first predetermined temperature t0 at a step S162.

If the coolant temperature is lower than the first predetermined temperature t0, the control unit 50 turns off the pump 60 at a step S190. If the coolant temperature is lower than the first predetermined temperature t0, heat loss may occur by operation of devices such as a heater in the vehicle. Therefore, the pump is turned off so as to prevent heat loss of the coolant.

If the coolant temperature is not lower than the first predetermined temperature t0, it is determined whether the oil temperature is lower than a second predetermined temperature t1 at a step S164.

If the oil temperature is lower than the second predetermined temperature t1, the control unit 50 turns on the pump 60 at a step S192. That is, since the oil temperature is low, the automatic transmission 80 and the differential apparatus 70 are warmed up quickly by performing heat exchange between the oil and the coolant. Therefore, in order to raise heat-exchange efficiency between the oil and the coolant, the pump 60 is turned on.

If the oil temperature is not lower than the second predetermined temperature t1, it is determined whether the oil temperature is lower than a third predetermined temperature t2 at a step S166. Herein, the second predetermined temperature t1 is lower than the third predetermined temperature t2.

If the oil temperature is lower than the third predetermined temperature t2, the control unit 50 turns off the pump 60 at a step S194. When the oil temperature is higher than or equal to the second predetermined temperature t1 and is lower than the third predetermined temperature t2, the oil can lubricate the automatic transmission 80 and the differential apparatus 70 sufficiently without the operation of the pump. Therefore, the pump 60 is turned off so as to minimize wasting energy of the heat exchange system according to various embodiments of the present invention. If the oil temperature is not lower than the third predetermined temperature t2, the control unit 50 turns on the pump 60 at a step S196.

The third predetermined temperature t2 is substantially high. If the oil temperature is raised too high, the automatic transmission 80 and the differential apparatus 70 may be overheated. Therefore, the oil should be cooled.

If the oil temperature is higher than or equal to the third predetermined temperature t2, the oil should be cooled by heat-exchanging with the coolant. Therefore, the pump 60 is turned on so as to enhance the heat-exchange efficiency between the oil and the coolant.

The first, second, and third predetermined temperatures t0, t1, and t2 can be set arbitrarily by a person skilled in the art. In addition, three predetermined temperatures are used in various embodiments of the present invention, but is not limited to this. A series of a plurality of predetermined temperatures can be used.

As described above, since a heat exchange system is applied simultaneously to an automatic transmission and a differential apparatus, heat-exchange between oil and coolant may be performed efficiently and fuel consumption of a vehicle may be reduced according to various embodiments of the present invention.

In addition, since three fluids are heat-exchanged with each other in one heat exchanger, unnecessary cooling loss may be minimized and durability of a driving device may be improved.

For convenience in explanation and accurate definition in the appended claims, the terms upper or lower, front or rear, inside or outside, and etc. are used to describe features of the exemplary embodiments with reference to the positions of such features as displayed in the figures.

The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and their practical application, to thereby enable others skilled in the art to make and utilize various exemplary embodiments of the present invention, as well as various alternatives and modifications thereof. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents. 

1. A heat exchange system for a vehicle, comprising: a heat exchanger adapted to transfer heat among a coolant, an automatic transmission oil, and/or a gear oil; an engine fluidly connected to the heat exchanger and adapted to deliver the coolant to the heat exchanger or to receive the coolant from the heat exchanger; an automatic transmission fluidly connected to the heat exchanger and adapted to deliver the automatic transmission oil to the heat exchanger or to receive the automatic transmission oil from the heat exchanger; a differential apparatus fluidly connected to the heat exchanger and adapted to deliver the gear oil to the heat exchanger or to receive the gear oil from the heat exchanger; a pump adapted to pump the gear oil; and a control unit adapted to control the pump.
 2. The heat exchange system of claim 1, wherein a coolant pathway through which the coolant flows, a transmission oil pathway through which the automatic transmission oil flows, and a gear oil pathway through which the gear oil flows are formed in the heat exchanger, and the coolant pathway, the transmission oil pathway, and the gear oil pathway are not fluidly communicated with each other.
 3. The heat exchange system of claim 2, wherein the coolant, the automatic transmission oil, and/or the gear oil transfer heat with each other during passing respectively through the coolant pathway, the transmission oil pathway, and/or the gear oil pathway.
 4. The heat exchange system of claim 1, wherein the pump is provided at the differential apparatus.
 5. The heat exchange system of claim 1, wherein the control unit is adapted to receive information on the coolant, the automatic transmission oil, and/or the gear oil, and to control a rotation speed of the pump or to turn on or off the pump selectively based on the information.
 6. The heat exchange system of claim 1, further comprising: a heater adapted to receive the coolant from the engine, warm up the coolant and return the coolant back to the engine; and a radiator adapted to receive the coolant from the engine, cool the coolant and return the coolant back to the engine.
 7. A control method of a heat exchange system which circulates a coolant through an engine, a gear oil through a differential apparatus with a pump, and an automatic transmission oil through an automatic transmission, the method comprising: determining whether information on temperatures of the coolant, the automatic transmission oil, and the gear oil is received during an operation of the engine; calculating a rotation speed of the pump according to the information if the information is received; and operating the pump according to the calculated rotation speed.
 8. The control method of claim 7, wherein the pump is operated at a safe mode if the information is not received.
 9. The control method of claim 7, wherein the pump is operated only when the engine operates.
 10. The control method of claim 7, further comprising diagnosing the pump if a vehicle is in a key-on state before the engine operates.
 11. A control method of a heat exchange system which circulates a coolant through an engine, a gear oil through a differential apparatus with a pump, and an automatic transmission oil through an automatic transmission, the method comprising: determining whether information on temperatures of the coolant, the automatic transmission oil, and the gear oil is received during an operation of the engine; and turning on or off the pump selectively based on the information if the information is received.
 12. The control method of claim 11, wherein the pump is turned off to prevent heat loss of the coolant when a coolant temperature is lower than a first predetermined temperature.
 13. The control method of claim 12, wherein the pump is turned on to increase a heat-exchange efficiency between the oil and the coolant when the coolant temperature is higher than or equal to the first predetermined temperature and an oil temperature is lower than a second predetermined temperature.
 14. The control method of claim 13, wherein the pump is turned off to minimize wasting energy of the heat exchange system when the oil temperature is higher than or equal to the second predetermined temperature and is lower than a third predetermined temperature.
 15. The control method of claim 14, wherein the pump is turned on to prevent overheating of the automatic transmission and the differential apparatus when the oil temperature is higher than or equal to a third predetermined temperature.
 16. The control method of claim 11, wherein the pump is operated at a safe mode if the information is not received.
 17. The control method of claim 11, wherein the pump is operated only when the engine operates.
 18. The control method of claim 11, further comprising diagnosing the pump if a vehicle is in a key-on state before the engine operates.
 19. The control method of 10, further comprising operating a warning device to alert a drive if the pump is not operated normally.
 20. The control method of 19, wherein the warning device is a warning lamp. 